Numerical Simulations of the Formation of Hurricane Fred (2009)

The goal of this study is to understand the genesis processes and the large-scale influence of hurricane Fred (2009). The Weather Research and Forecasting model with a 20 km grid is used. The preliminary results demonstrated the model predicted a vortex at 0000 UTC 7 September 2009 around 13oN, 19oW near the Cape Verde islands. The northward turn of Fred occurred between 0000 UTC 10 and 0000 UTC 11 of September. Subsequently, Fred turned northeastward by 0000 UTC September 12. The intensity was decreasing during this period. In addition to hurricane Fred, there was a new vortex simulated by the model at 0000 UTC 13 September. Overall, the model was able to recapture this event. However, there are several unanswered questions need to be addressed. In this study we will be investigating 1) the possible factors (wind shear and/or SST) contributing to the deepening and turning of hurricane Fred; 2) To what extent is the model able to predict TC genesis; and 3) Are there any interactions between the two vortices in the later stage of this case?